Federal agents and marines seized seven tons of ethyl phenylacetate, a chemical that can be used to manufacture designer drugs, in the Mexican Pacific port of Manzanillo, officials said.

The chemicals were found inside 35 metal barrels, each with a capacity to hold 200 kilograms (440 pounds), according to a joint statement from the Attorney General's Office and the Navy Secretariat.

Ethyl phenylacetate is listed as a psychotropic compound and a synthetic-drug precursor in Mexico, the statement said, adding that the AG's office is continuing to investigate the consignment.

Mexico's Pacific region is where chemicals for processing synthetic drugs usually arrive, as well as being the center for the production of crystal meth and the smuggling of cocaine from South America.

Mexico, which produces most of the crystal meth consumed in the United States, has tightly restricted imports of chemicals used in the production of illegal synthetic drugs.

A total of 200 tons of drug-precursor chemicals were confiscated in Manzanillo last August, a record seizure in Mexico.